Poppy, I recently wrote an article on niobium that was published in
the Sept. 2001 issue of Lapidary Journal that you might find
interesting. It features the work of a number of artists who use
niobium, plus a little bit of description about working with it.
That issue also includes John Flynn’s Step by Step article describing
the process for making a pair of niobium earrings, including fusion
welding the posts.
The short answer to your question is that you can’t solder niobium
wire. If I understand the problem correctly, the niobium forms oxides
when heated, which prevents a good solder bond. (Bill Seeley or
someone else more knowledgable than me may want to jump in here!)
That oxides are also what gives niobium its color, so yes, heating it
will affect the color of the metal – Rick Hamilton intentionally
heats niobuim to get a dark charcoal to black color, for example.
Hope that helps!
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